This document is an introduction to parasitology, highlighting essential definitions related to parasites, hosts, vectors, and zoonosis, along with the types of organism relationships and parasite life cycles. It discusses medical parasitology and the impact of parasites on human health, including their modes of infection and preventive measures. The text also categorizes parasites into protozoa, helminths, and ectoparasites, outlining their characteristics and transmission methods.

1. CHAPTER 1
INTRODUCTION TO
PARASITOLOGY
BT1092 PARASITOLOGY
DIPLOMA IN MEDICAL LABORATORY TECHNOLOGY
MDM SITI BAINUN BINTI MOHD DALI

2. LEARNING
OUTCOME
01 Define parasite, host,
vector, zoonozis
02
Defines types of
organism relationships
03
Discuss the life
cycles of parasites
04
Explain modes of
infection
At the end of this lecture,
students should be able to:

3. INTRODUCTION
01

4. Fields In Medical Microbiology
Bacteriology
Virology
Parasitology
Mycology
The study of bacteria
The study of viruses
The study of parasites
The study of fungi

5. ● Parasitology is the branch of microbiology concerned with the
phenomenon of dependence of one living organism on another.
 Medical parasitology deals with
 the parasites which infect man,
 the disease they produce,
 the response generated by our body against the parasite
 various methods of diagnosis and prevention.
PARASITOLOGY

6. ● Parasite: a living organism which receives nourishment and shelter from another
organism where it lives
● Host: an organism which harbours the parasites
● Vector: a vector is an agent, usually an insect, that transmits an infection from
one human host to another
● Zoonosis: it means a disease of animals. Leishmaniasis, trypanosomiasis,
trichinelliasis and echinococcosis
TERMINOLOGY

7. Type of Hosts
Definitive
host
Host in which the
sexual reproduction
of parasite takes
place
Reservoir
host
Organism in which a parasite
that is pathogenic for some
other species, lives and
multiplies usually without
damaging its host
Intermediate
host
Used normaly by a
parasite in the course
of it life cycle, in which
it may multiply
asexually and but not
sexually

8. 1. PREPATENCY
● The phase of the disease between infection and the
appearance of diagnosable parasite stages
○ The appearance of tape worm eggs in the faeces
○ Malaria parasites in a routine blood smear
● This time frame can change with improvements in the
sensitivity of diagnostic assays
● A patent infection is thus at an established diagnosable
stage.
DISEASE TERMINOLOGY

9. 2. Incubation period:
○ time between infection and the development of symptoms (signs of
disease like fever, pain or discomfort)
3. Acute disease
○ Have relatively quick onset and short duration
○ Symptoms worsen into a crisis and then the disease resolve
spontaneously into healing, results in the death of the patient or
transforms into chronic disease.
4. Chronic disease
○ Develop slowly, persistent and might show no symptoms
○ The parasite survives or persists over time (can be the rest of the life
of the patient)
DISEASE TERMINOLOGY

10. PARASITE
 organism that lives on or in a host organism and gets its food from or at
the expense of its host.
 3 main types:
 Protozoa eg. Plasmodium spp.
 Helminthes eg. hookworm, roundworm, tapeworms
 Ectoparasites (Arthropods) eg. lice, fleas, mites

11. 1. Protozoa :
○ single-celled organisms that generally
live inside the body of the host.
○ Includes malaria, ciliates, flagellates an
amoeba
○ they obtain nutrition from the host and
are able to multiply and increase in
number.
○ can be transmitted from one host to
another
CLASSIFICATION OF
PARASITES

13. 2. Helminths:
○ Multicellular parasites that tend to be
bilaterally symmetrical
○ helminths are endoparasites
○ Include members of cestode,
trematode, and nematodes
○ Using suckers or hooks (found in
cestodes and trematodes), to remain
attached to the walls of the
gastrointestinal tract and continue
absorbing nutrients.
CLASSIFICATION OF
PARASITES

14. 3. Arthropods
○ Multicellular organisms that are
bilaterally symmetrical
○ arthropods are ectoparasites
(attached to the skin of the host)
○ have joined appendages used for
movement and attachment as well as
hard exoskeleton that protects the
internal organs of the parasites.
○ Examples of arthropods include lice,
fleas, and ticks.
CLASSIFICATION OF
PARASITES

16. PROTOZOAN

17. PROTOZOA
Amoeba
Intestinal
amoeba
Free living
amoeba
Flagellates
Intestinal
flagellates and
ciliates
Blood and
Tissue
flagellates
Sporozoan
Intestinal
sporozoan
Blood and
tissue
sporozoan

18. LIFE CYCLE
● Parasite stages are shown in the
outer circle and hosts in the
centre

19. PORTAL OF ENTRY INTO THE BODY
Mouth
Sexual contact
Congenital
Kissing
Skin
Inhalation

20. 1. Direct contact: transmitted from an infected site to another site
2. Congenital: some parasite can cross the placental barrier from
mother’s blood to the unborn fetus. Eg: malaria and toxoplasmosis
3. Ingestion: food and water contaminated with ova or larvae
4. Arthropod-borne: arthropods serve as vectors
5. Active penetration: larval stage may have the capability of
penetrating the host tissues
6. Transfusion: certain blood and tissue parasites.
MODE OF INFECTION

21. ● The individual, as well as the community, must get involved in the
prevention of parasitic infections
● Life cycles of parasites may be interrupted by eradication of the
vectors
● Education about hygiene, eating habits and disposal of human and
animal wastes can also be used in combating parasites
● Treatment of diseased individuals not only relieves the suffering,
but also prevents the spread of the disease
PREVENTIVE MEASURES

22. THANK YOU!